Battery energy storage systems (BESS) have moved from a niche grid technology to a core pillar of the U.S. energy transition. The market set another record in 2025 with nearly 19 GW of new installations—up more than 50% year over year—and industry forecasts call for roughly half a terawatt-hour of additional capacity by 2031. Grid-scale and solar-paired storage keeps the grid stable, and it unlocks compelling economics for owners and infrastructure investors through value stacking.
Multiple, stackable revenue streams
Unlike a solar array with a single offtake contract, a well-sited battery can earn revenue several ways at once:
- Energy arbitrage: charge when power is cheap, discharge when it is expensive
- Capacity payments: get paid to be available during peak demand
- Ancillary services: frequency regulation and reserves that keep the grid balanced
- Resilience: backup power that carries a premium for critical loads
Stacking these streams ("value stacking") is what drives attractive BESS returns, but it requires sophisticated dispatch modeling and market access.
What drives project economics
The key variables in a storage investment are:
- Duration: how many hours the battery can discharge at full power (typically 2–4 hours, with longer-duration systems emerging for data-center and reliability applications)
- Cycling: how often the battery charges and discharges, which affects both revenue and degradation
- Market structure: the wholesale and capacity markets available in the project's region
- Augmentation: the plan to add capacity over time as cells degrade
Interconnection timelines and upgrade costs can materially affect storage project schedules and returns.
Solar-paired vs. standalone
Storage can be paired with solar to firm output, or built as a standalone merchant or contracted asset. Solar-plus-storage configurations often improve project economics versus solar alone. Each structure carries a different risk-return profile.
A tax-credit advantage over solar
Storage now holds a structural edge in federal tax policy. While the One Big Beautiful Bill Act phases out the ITC for solar and wind, energy storage retains full Section 48E credit eligibility for projects that begin construction through 2033, with a gradual step-down thereafter. Projects beginning construction after 2025 must satisfy foreign-entity-of-concern (FEOC) sourcing rules—a minimum share of non-prohibited equipment cost that starts at 55% in 2026 and rises to 75% by 2030—making supply-chain diligence a core part of storage underwriting.
Demand from data centers
Surging data-center load is reinforcing storage economics. Large-load customers are signing colocation and capacity contracts with storage providers to get online faster and manage peak demand, and utility-scale storage is expected to dominate capacity additions through the end of the decade. Data centers have become a meaningful new offtake channel for BESS alongside traditional grid services.
How Sunlight approaches storage
Sunlight Energy Investments finances, develops, and operates grid-scale and solar-paired storage across U.S. markets. We underwrite conservative dispatch assumptions and structure contracts that lenders and tax-equity partners will finance.
To discuss a storage opportunity, book a consultation or contact our team.